John Gill Commentary Deuteronomy 7:15

"And Jehovah will take away from thee all sickness; and none of the evil diseases of Egypt, which thou knowest, will he put upon thee, but will lay them upon all them that hate thee." — Deuteronomy 7:15 (ASV)

And will take away from you all sickness
Bodily sickness and diseases, prevent the coming of them, or remove them when come:

and will put none of the evil diseases of Egypt which you know
upon you ;
meaning either the plagues that were inflicted upon them to oblige them to let the Israelites go, of which they had perfect knowledge; or else some noxious and nauseous diseases, which were common among, and peculiar to, the Egyptians, particularly what is called the botch of Egypt; see (Exodus 15:26) , likewise the leprosy; (See Gill on Leviticus 13:2), (See Gill on Deuteronomy 28:27).

but will lay them upon all them that hate you ;
with which God sometimes punishes his and his people's enemies; see (Judges 5:9) (Revelation 16:10Revelation 16:11) .